Jesus is the Messiah.
He has yet to meet a single qualification for the job, other than being Jewish.
How do you know that it isn’t Bar Kochba - he at least fought foreign armies successfully to make Israel free and unite the Jewish people. There is also some evidence that he was starting to build the 3rd Temple. He was also Jewish, and descended on his father’s line from King Solomon. That’s quite a bit more, according to Jewish scripture, than Jesus ever did. So why can’t it be him... because he’s dead?